GM-CSF-Induced Metal Sequestration and Histoplasma

这种致病真菌，组织胞浆菌，是美国中西部和东南部的特有真菌， 是呼吸道真菌感染最常见的原因。这种有机体在 单核细胞(Mo)和巨噬细胞(Mɸ)的细胞内环境，并具有 建立一种潜伏状态。采用多学科方法，包括金属组学、免疫学、 细胞生物学和生物信息学，我们的研究发现了粒细胞的新功能 巨噬细胞集落刺激因子(GM-CSF)和IL-4有助于解释其 Mo/Mɸ对真菌生长的不同影响。GM-CSF剥夺了机体的锌 在细胞内，同时促进活性氧物种的产生。最终的结果是 就是杀死酵母细胞。另一方面，IL-4通过增强细胞内的 组织胞浆体可利用的锌量。对GM-CSF和IL-4的活性至关重要的是 储存和捐赠锌的金属硫蛋白(MTS)和锌转运蛋白。它们是一个中心节点 调节细胞因子激活和效应器功能之间的联系。对于GM-CSF，MTS1和MT2为 而对于IL-4来说，它是MT3。在这项建议中，我们将在我们在 上一个资金周期，并深入探讨MT-锌轴如何调节GM-CSF的活性 人和小鼠Mo/Mɸ上的IL-4。我们收集了令人兴奋的数据，糖酵解控制着 感染GM-CSF刺激的Mo/Mɸ中MTS1和MT2的表达另一方面，MT3磨练了 IL-4的糖酵解反应在这些细胞中被激活。目标1将破译糖酵解如何塑造 Mt1&2表达和细胞内锌分布增强Mo/Mɸ效应功能。目标2 将定义GM-CSF激活的Mo/Mɸ中的细胞内变化，这些变化使真菌无法进入 锌和体内MTs1和2对这些吞噬细胞所产生的宿主防御的影响。目标3将 阐明糖酵解和MT3在形成IL-4生理过程中的交集 组织胞浆感染的Mo/Mɸ。这些研究将为细胞因子的调控提供新的见解。 组织胞浆感染的Mo/Mɸ的代谢和金属生物学

The pathogenic fungus, Histoplasma capsulatum, is endemic to the Midwestern and Southeastern US and is the most frequent cause of respiratory fungal infection. The organism thrives within the intracellular environ- ment of monocytes (Mo) and macrophages (Mɸ) and has the capacity to establish a latent state. Employing a multidisciplinary approach including metallomics, immunology, cell biology and bioinformatics, our studies have identified novel functions of granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 that help to explain their disparate effects on the growth of the fungus with Mo/Mɸ. GM-CSF deprives the organism of zinc intracellularly while concurrently boosting production of reactive oxygen species. The end result is killing of yeast cells. On the other hand, IL-4 promotes intracellular survival by fortifying the amount of zinc available to Histoplasma. Crucial to the activities of GM-CSF and IL-4 are metallothioneins (MTs), which store and donate zinc, and zinc transporters. They are a central node mediating the link between cytokine activation and effector function. For GM-CSF, MTs1 & 2 are essential whereas for IL-4, it is MT3. In this proposal, we will build on our work conducted during the last funding cycle and explore in depth how the MT- zinc axis regulates the activity of GM-CSF and IL-4 on human and mouse Mo/Mɸ. We have collected exciting data that glycolysis governs the expression of MTs1&2 in infected GM-CSF-stimulated Mo/Mɸ. On the other hand, MT3 tempers the glycolytic response in IL-4 activated in these cells. Aim 1 will decipher how glycolysis molds MT1&2 expression and intracellular Zn2+ distribution to bolster Mo/Mɸ effector function. Aim 2 will define the intracellular alterations in GM-CSF-activated Mo/Mɸ that deny the fungus access to zinc and the in vivo effect of MTs1&2 on host defenses exerted by these phagocytes. Aim 3 will elucidate the intersection of glycolysis and MT3 in shaping the physiology of IL-4 on Histoplasma-infected Mo/Mɸ. These studies will provide new insights into cytokine regulation of metabolism and metallobiology in Histoplasma-infected Mo/Mɸ.